[Test-Equipment] Ideas ?

[George Shaw]

Folks

I am looking for ideas for the following, and of course though some of =
you
would have a few ideas.

I need to attach a Data Logger device to a series of relays. There is =
not
always spare contacts on the relays and I can NOT add wires to the =
existing
relays. The logger simply records change of state form say de-energised =
to
energised (open-closed, picked-dropped, No - Nc, power on power off)
switching at the moment via the negative wetting voltage supplying spare
contacts that mirror the actions of the ones being monitored.

I am looking for a Cheap induction type clamp on device (up to 38 =
channels
need to be monitored so each logger will require 38 of the devices). The
inputs to the logger are + and - with logging taking place when a =
voltage is
applied or dropped (+ V detected =3D Bit 1,  - V detected bit 0 change =
from
bit 1 to 0 =3D change in state). I am happy to build such devices or to
purchase if cost is within reason.

Any ideas or products/designs circuits welcome.

--
George Shaw MI3GTO

" Any Sufficiently Advanced Technology
is Indistinguishable from Magic"
                          ---Arthur C. Clarke

Mobile: +44 (0) 7740 361 163
Email: george.shaw@ukf.net
Fax & Voicemail: +44 (0) 871 242 9183